Fuel injection system for internal combustion engine

ABSTRACT

A fuel injection system for an internal combustion engine wherein fuel is pumped at a low pressure into a nozzle disposed within and extending across the intake manifold. The fuel is metered at the metering valve in response to the opening of the throttle valve in the intake manifold to provide a fuel/air ratio affording the proper operation of the internal combustion engine. The metering valve preferably has an electrically operated shutoff valve operated by the ignition switch of an automobile to close the fuel line in advance of the metering valve when the engine is shut off to avoid a surge of fuel from the pump from entering the engine. The fuel is pumped to the metering valve by a suitable fuel pump which pumps the fuel through a pressure regulator into the fuel line leading to the metering valve. A port injector nozzle which extends across the inside cylindrical area of the manifold has a plurality of restricted bores positioned in spaced relation along the length of the generally cylindrical shaped nozzle. The air flow about the nozzle reduces the pressure on the downstream side of the nozzle drawing fuel from the nozzle and vaporizing the fuel. An idle passageway formed in the wall of the intake manifold opens into the intake manifold adjacent an edge of the throttle valve such that the fuel entering the engine during idle operation is also drawn from the idle passageway and atomized before it is carried into the engine intake manifold.

United States Patent [191 Barilbeau et al,

[ 1 FUEL KNJEGTKON SYSTEM FOR llNTERNAL CDMBUSTKDN ENGHNE [76] Inventors: Ronald D. Baribeau, 112 N.

Greeley; Russell A. Bariheau, 317 E. Churchill, both of Stillwater, Minn. 55082 [22] Filed: Apr. 16, 1973 [21] Appl. No.: 351,480

Related ILLS. Application Data [63] Continuation-in-part of Ser. No. 318,376, Dec. 26, 1972, which is a continuation-in-part of Ser. No. 146,627, May 25, 1971, abandoned.

[52] 11.5. C1 2611/41 D, 261/DIG. 39, 261/51, 261/78 R, 261/116, 123/139 AW [51] int. Cl. F02m 69/04, F02d 3/02 [58] Field of Search 261/78 R, DIG. 39, 76, 261/41 B, 41 R, 41 D, 116, 51, 62; 239/596, 567; 123/139 AW [56] References Cited UNITED STATES PATENTS 1,103,930 7/1914 Bennett 261/41 R 1,758,954 5/1930 Linn 261/D1G. 39 1,855,383 4/1932 Capell 261/D1G. 39 2,136,959 11/1938 Winfield 261/41 R 2,626,137 l/1953 Tapley 261/41 R 2,689,116 9/1954 Richardson.... 261/51 2,995,349 8/1961 Kennedy, Sr... 261/41 R 3,018,093 1/1962 Powell 261/41 R 3,235,236 2/1966 Kalert, Jr. 261/78 R 3,362,694 1/1968 Gould 261/50 A 3,618,581 11/1971 Simonet 261/69 R 11] 3,834,679 [451 Sept. 10, 1974 Primary ExaminerTim R. Miles Attorney, Agent, or Firm-.lohn G. Barnes, Esq.

[5 7] ABSTRACT A fuel injection system for an internal ,combustion engine wherein fuel is pumped at a low "pressure into a nozzle disposed within and extending across the intake manifold. The fuel is metered at the metering valve in response to the opening of the throttle valve in the intake manifold to providev a fuel/air ratio affording the proper operation of the internal combustion engine. The metering valve preferably has an electrically operated shutoff valve operated by the ignition switch of an automobile to close the fuel line in advance of the metering valve when the engine is shut off to avoid a surge of fuel from the pump from entering the engine. The fuel is pumped to the metering valve by a suitable fuel pump which pumps the fuel through a pressure regulator into the fuel line leading to the metering valve. A port injector nozzle which extends across the inside cylindrical area of the manifold has a plurality of restricted bores positioned in spaced relation along the length of the generally cylindrical shaped nozzle. The air flow about the nozzle reduces the pressure on the downstream side of the nozzle drawing fuel from the nozzle and vaporizing the fuel. An idle passageway formed in the wall of the intake manifold opens into the intake manifold adjacent an edge of the throttle valve such that the fuel entering the engine during idle operation is also drawn from the idle passageway and atomized before it is carried into the engine intake manifold.

9 Glaims, 3 Drawing Figures PAIENTEDSEPIOW 3.834.679

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FUEL INJECTION SYSTEM FOR INTERNAL COMBUSTION ENGINE RELATED APPLICATION This application is a continuation-in-part of application Ser. No. 318,376, filed Dec. 26, 1972, which is a continuation-impart of application Ser. No. 146,627, filed May 25, 1971, now abandoned. A continuation application of Ser. No. 146,627 filed as Ser. No. 349,955, is now US. Pat. No. 3,800,770.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a fuel injection system for internal combustion engines to place a predetermined quantity of vaporized fuel, i.e., standard brands of gasoline, into the air stream moving into an internal combustion engine. In the system of the present invention the amount of fuel moving into the engine is determined in response to the position of the throttle valve and the amount and velocity of the air entering the engine and the pressure on the fuel moving it into the nozzle. The system increases the performance from the internal combustion engine by the high air/fuel ratio and the efficient transition of the fuel at the nozzle to a vapor. The system efficiency depends on the availability of fuel in the nozzle at sufficient pressure to drive the fuel across the nozzle or across the intake port to distribute the vaporized fuel into all the air entering the engine.

2. Description of the Prior Art Previously known fuel port injection systems of a low pressure type, i.e., a pressure of 15 lbs. gauge or less have utilized a nozzle which merely dumps the fuel into the air stream without any efficient atomization. Thus fuel in the liquid phase was running into the intake manifold and the same was generally wet. Thenozzles in the prior art systems are located in a side wall of the intake manifold and, whether on the vacuum or pressure side of the throttle valve, or at the throttle valve the fuel was not distributed at the time of introduction throughout the flow of air into the engine in a vaporous state.

Some of the prior known patents disclosing port injectors include May U.S. Pat. No. 3,525,403, Winquist US. Pat. No. 3,510.1 l2, and Hilbom US. Pat. No. 3,656,464. Other patents may exist but these patents all teach the positioning of the nozzle at the throttle valve or on the vacuum side of the throttle valve. These systems use the pressure of the fuel to atomize the fuel by ajet being directed to impinge on a member in the path of the jet. Atomization or the breaking up of a liquid into small droplets does not provide the degree of efficiency that a vaporization and uniform mixing of fuel with all the air can provide. Thus, the prior art port injection systems have not provided efficiency exceeding carburetion systems.

SUMMARY OF THE INVENTION The present invention provides a fuel system wherein the fuel is forced into a nozzle extending across the path of the air being drawn into an internal combustion engine. The air draws the fuel from the nozzle by reducing the pressure at the bores in the nozzle and the pressure reduction is believed to be sufficient that a transition takes place. The fuel, gasoline, is apparently vaporized'as it leaves the tiny bores in the nozzle and a chilling of the intake manifold adjacent the nozzle results. These factors plus the cooler operating temperature of the engine is evidence of the vaporization of the fuel.

The system of the present invention is adapted for attachment to an engine and comprises an intake manifold portion or throat, a throttle valve in the intake manifold near the outlet end, a slender cylindrical nozzle extending across the manifold normal to the direction of air movement, and a metering valve for metering amounts of fuel to the nozzle in response to movement of the throttle valve. Fuel is pumped to the metering valve through an accumulator to maintain a predetermined pressure on the fuel at the metering valve. Due to the presence of the pressure provided by the pump or pump and accumulator. it is preferable to have a shut-off valve at the metering valve to avoid the dumping of fuel in the system into the engine when the engine is stopped.

The nozzle in the system is positioned up stream or on the positive pressure side of the throttle valve. The positioning of the nozzle and its size and the size of the bores therein relate to its operation. The pump must also provide sufficient pressure on the fuel such that when it reaches the nozzle it will be forced through the nozzle and completely across the intake throat to cause a vaporization of the fuel from all the bores spaced along the length of the nozzle.

The system provides a structure to afford smooth idling for the engine by positioning the throttle valve such that the peripheral edge thereof is positioned at the idle bypass opening in the wall of the intake manifold. This produces a vaporization of the fuel at this opening as the air is drawn around the throttle valve.

This injection system of this invention provides increased engine performance. There is an increase in horsepower and a reduction in fuel consumption. The engine will operate at a cooler temperature. This will increase the life of the valves, muffler and other members subjected to high heat on internal combustion engmes.

BRIEF DESCRIPTION OF THE DRAWING The present invention will be better understood upon a perusal of the following detailed description which refers to the accompanying drawing wherein:

FIG. I is a schematic view showing a fuel injection system constructed according to the present invention and showing the intake manifold throat portion in vertical section;

FIG. 2 is an enlarged detail vertical sectional view of the intake manifold showing the fuel injection nozzle, throttle valve, and idle bypass passageway; and

FIG. 3 is a sectional view of the metering valve for the fuel injection system.

DESCRIPTION OF THE PREFERRED EMBODIMENT The operation of the fuel injection system of the present invention comprises the pumping of fuel, commercial gasoline, through a fuel line 6 from a storage reservoir 7 by a fuel pump 8. The output from the fuel pump 8 is pumped into a fuel line 9 past a air or vapor return member 10, through an accumulator 12 and fuel line I3 to a check or shut-off valve IS. The valve 15 is connected to a metering valve 25 which controls the flow of fuel to a nozzle 36 in an intake manifold 38 or throat of the intake manifold in response to the movement of the throttle valve 50.

In the illustrated system the pump 8 may be a conventional lever operated, cam driven, diaphragm pump for most applications. When the engine will be operated at RPMs in excess of the response cycle which the pump is capable of attaining, as in racing engines, the pump can be an electric pump or belt driven pump of the continuous or pulsating type. it is desired that the pump provide fuel at a pressure from 1 to 15 lbs. gauge to provide sufficient pressure for a wide range of engine sizes, however, a pump with a capacity of only 6 lbs. pressure gauge is sufficient for most small economy sized automobile engines of 1,600 to 2,400 cubic centimeters or 90 to 140 cubic inches.

The accumulator 12 provides for an even predetermined pressure on the fuel when a pulse type pump (diaphragm or piston type) is used. One example of an adjustable accumulator or pressure regulator for liquids which is usable in the system of the present invention is illustrated in U.S. Pat. No. 3,357,687. It is preferable that the accumulator be adjustable permitting the proper pressure adjustment when adjusting the system.

Between the pump 8 and accumulator 12 is the vapor return member 10. This member may be a vapor trap which comprises a chamber through which the fuel will flow and which has a restricted return to the fuel tank or reservoir 7. As illustrated the vapor return member is a T-shaped fitting. This tee is formed with a restricted passage 14 leading to a return line 11. The vapor return member affords the separation of any air that might have been pumped from the tank 7 with the fuel, and small amounts of fuel, to be returned through the line 11 to the tank 7. The vapor separating and return member can be placed in the system at most any place between the pump and the flow control or metering valve 25. It is necessary that the air bubbles forming or pumped from the tank be removed as they cause irregular ignition in the engine and performance is reduced if the air is allowed to reach the injection nozzle.

The check or shut-off valve 15 is preferably a solenoid actuated valve connected in series to the ignition switch in an automobile for purposes of convenience. The valve could be mechanically operated as well. The valve 15 as illustrated is formed with an inlet chamber 16 closed at the outlet by the head on a plunger 17. The plunger fits over the outlet opening communicating between the inlet chamber 16 and a discharge passageway 19. The plunger 17 is biased to the closed position by a spring 20 and opened against the bias of the spring by energizing a coil 21. The coil 21 will be de-energized upon opening the switch to the ignition. The check valve 15 will then close under the bias of the spring 20 to prevent a surge of fuel under the pressure of the pump and/or accumulator from being dumped into the engine causing it to flood and making it difficult to restart immediately.

The shut-off valve 15 could be connected to a separate switch or the shut-off valve for the gas line can be a mechanical valve operated by a cable from within the automobile.

Metering valve 25, as seen in FIGS. 1 and 3, comprises a rectangular block or frame member having a bore 26 in which is fitted a rod 27 with a central bore 28 extending partially therethrough. The bore 28 forms a passageway from an inlet fitting 29 which holds the rod 27 in place. Fitting 29 is also axially bored forming a passageway for fuel into the bore 28 and is connected to the shut-off valve 15. A radial or lateral slot 31 is formed in the rod 27 which slot 31 is moved upon rotation of rod 27 to expose varying amounts of the slot to a passageway 33 leading to a fuel line 35 directed to the nozzle 36, thus metering the amount of fuel to pass to the nozzle 36 by changing the size of the passageway for the fuel at a given pressure.

The nozzle 36 is fitted into the intake manifold throat portion 38. The manifold 38 is a short section having preferably a cylindrical inner passage. One end of the manifold 38 is formed with a flange 39 adjacent the outlet end permitting it to be bolted to the intake manifold of the engine. The internal diameter of the manifold 38 is about 1 and 5/8 inches and this size can be used with most engines to 5,000 cubic centimeters or 300 cubic inches. Racing engines or larger vehicle engines may use a plurality of intake manifolds and thus a separate injection system for each.

The nozzle 36 extends diametrically through the intake manifold along a diameter normal to the axis of the rod supporting the butterfly or equivalent throttle valve 50. The nozzle 36 is formed to have a slender cylindrical portion extending into the manifold and to have at one end an enlarged portion to receive the fuel line 35. The slender portion of the nozzle 36 has an outside diameter of between 0.060 to 0.20 inch and has a restricted central bore 40 extending therethrough with a diameter of between 0.020 and 0.125 inch. A plurality of spaced restricted transverse bores 41 and 42 are formed symmetrically in the nozzle, said bores 41 and 42 having a diameter of between 0.020 and 0.100 inch. Preferably, the bores 41 adjacent the ends of the slender cylindrical portion of the nozzle 36, and positioned closest to the walls of the manifold 38, extend diametrically through the cylindrical nozzle and communicate with the central bore. These transverse bores 41 have a diameter of between 0.040 and 0.10 inch and the transverse bores 42 which are parallel but which extend only half way through the rod are smaller in diameter and are between 0.020 to 0.060 inch. The restricted bores 41 and 42 are positioned in spaced relation along the nozzle and are symmetrical along the length of the nozzle 36. A bore 44, called an idle bore is formed in the nozzle to direct fuel into an idle passageway 45 which is formed in the wall of the intake manifold 38. The passageway 45 connects with a small discharge opening 46 leading into the interior of the manifold 38.

A high speed control member 48 is preferably positioned in the fuel line 35 at the outlet from the metering valve 25 to control the amount of fuel leaving the metering valve when the butterfly is in a open throttle position and bore 31 is aligned with passageway 33. This valve consists of an adjustable set screw which may be threaded into the passageway of the fuel line 35 to restrict the same.

The throttle valve 50 in the intake manifold 38 is controlled by a cable or link 51 operated by a throttle or by a pressure peddle. The link 51 is connected to a crank arm 52 which is secured to a shaft 53 extending diametrically through the manifold 38. Within the manifold is the throttle valve in the form of a butterfly type valve which is circular and is secured to the shaft 53 for movement therewith. The valve 56} is biased by a torsion spring (not shown) to a closed or idle position which position is controlled by an adjustable stop member 54- as illustrated. The butterfly valve when in the idle position has its thin edge closely adjacent the wall of the intake manifold and is across the opening T6 of the idle passageway. in the idle position small amounts of air may enter the engine around the edge of the butterfly valve and this air plus the vacuum developed by the engine on the downstream side of the valve draws fuel out of the idle passageway into the intake manifold and thus into the engine. The air moving around the valve 50 at the opening 46 produces a partial restriction of the opening and vaporization of the fuel sufficiently to maintain a smooth idle running condition.

A link 55 is connected between a radial arm 56 connected to the shaft 53 and a radial arm 57 which is secure to and extends radially from the end of the rod 27 of the metering valve 25. The link 55 is adjustable lengthwise to permit adjustment of the slot 31 in the metering valve with the position of the throttle valve 50 to attain the correct amount of fuel with the air. As the position of the butterfly valve changes upon operation of the throttle the link transfers the motion to rotate the rod 27 opening or closing respectively the size of the opening between the bore 2% and the outlet passageway 33 to adjust the air/fuel ratio in the manifold.

The nozzle 36 is positioned on the pressure side of the valve Stl and the spacing of the nozzle from the valve may be adjusted for various sized engines to achieve the optimum position of the nozzle. llt is important that the fuel is introduced into the nozzle under sufficient pressure to load the central bore of the nozzle completely across the intake manifold. This pressure may vary depending on the velocity of the air rushing past the nozzle. For example, as the valve 50 opens the air moves along the top and the bottom edges of the manifold (as seen in FIG. 2), and if there is not enough pressure on the fuel all the fuel will be drawn from the first two bores $11. The velocity of the air and the pressure increases toward the center of the manifold as the valve 50 moves toward full throttle position. The air moving over or around the nozzle creates a vacuum on the bores 42 which are directed downstream of the air and it draws the fuel out of these bores and results in a transition of the fuel from the liquid to the vapor state as near as can be determined. The pressure on the fuel to the nozzle is necessary to load the entire nozzle for even distribution of the fuel across the manifold.

The vaporization of the fuel causes a cooling of the manifold and such a uniform mixture of the air and fuel, in a ratio of between 14-1 to 18-1, that the engine performance is improved without other changes. The damp cool air and fuel entering the engine causes it to operate 30 to 35F. cooler than with a carburetor fuel system. This temperature reduction will reduce damage to the valves and other parts subjected to the hot gases. The horsepower is increased as well as the mileage per gallon of gasoline. Performance tests in terms of increased acceleration from to 30 miles per hour or O to 60 miles per hour have been made using a Datsun pickup and the system of this invention has cut 2 seconds off a quarter mile time and one second off the 0 to 30 time to seconds and 7.3 seconds off the 0 to 60 time to a time lapse of 16.2 seconds from 23.5 seconds. Also, the fuel combustion is improved affording a cleaner engine by reducing the content 0 hydrocarbons in the exhaust gases. I

The port injection fuel system of this invention smooths the engine performance inthat the nozzle 36 has a built in velocity control. The air flow through the manifold must increase as the throttle valve is opened before greater amounts of fuel will be expelled from the nozzle. When the valve 50 is moved from one position to full throttle, the initial opening applies greater amounts of fuel to the nozzle so there will not be a lag but until the air flow increases as engine demand increases the fuel is not injected into the engine. The pressures on the fuel to load the nozzle are related to engine size and a pressure of 3 and A lbs. gauge is operative in cubic inch engines where 5 lbs. is more optimum in cubic inch engines. When placing this system on racing engines or engines. with superchargers the fuel pressure must be increased to assure the nozzle bore 4N) is filled across the manifold.

The elimination of air bubbles from the system, the adjustment afforded by the accumulator of the fuel pressure to the metering valve, and the adjustment of the fuel quantity and pressure to the nozzle by the link 55 and high speed adjusting screw 4-8 permits rapid adjustment of the engine performance.

Having thus described the invention with reference to a preferred embodiment, it will be understood that various changes may be made without departing from the spirit of the invention as defined by the appended claims.

We claim:

l. A port injection fuel system for an internal combustion engine comprising an intake manifold having a wall. defining an internal passageway through said manifold and having an inlet end and an outlet end, means at said outlet end adapted for attachment to a said engine, said wall having an opening defining a fuel discharge opening near said outlet end,

throttle valve means for controlling the flow of air through said intake manifold, said valve means having an open position and a closed position in said manifold to control air flow therethrough,

injection nozzle means comprising a slender hollow cylindrical rod disposed centrally across said manifold nearer said inlet end than said valve means and positioned normal to the axis of said intake manifold, said rod having a plurality of spaced bores positioned transverse thereto and axially of said intake manifold, for dispensing vaporized fuel into the air drawn through said intake manifold over said rod,

a fuel line connected to said nozzle means,

a flow control valve connected to said fuel line to meter the amount of fuel to pass through the line to said nozzle means, said valve comprising a movable valve member and means connected to said valve means for controlling the flow of air and to said valve member to increase the amount of fuel metered to said fuel line and said nozzle means as said throttle valve means is moved to increase the air flow through said intake manifold,

means for maintaining fuel in said flow control valve to be metered by said movable valve member to said nozzle means at a pressure sufficient to maintain fuel in said rod across the width of said manifold when said valve means is in said open position; and

means for removing air from the fuel line between said means for maintaining fuel in said flow control valve and said flow control valve.

2. A fuel system according to claim 1 wherein said means for maintaining fuel in said flow control valve comprises a pump and accumulator.

3. A fuel system according to claim 1 wherein said valve means restricts said opening in said wall in said closed position.

4. A fuel system according to claim 1 wherein said nozzle means is formed with a pair of restricted bores extending diametrically through said rod adjacent each end near the manifold walls and spaced bores extending only from the side of said rod toward the valve means to the center of said rod.

5. A fuel system according to claim 4 wherein said rod has an outside diameter of between 0.060 and 0.20 inch, a central bore of between 0.020 and 0.125 inch and said transverse bores have a diameter of between 0.020 and 0.10 inch.

6. A fuel system according to claim 1 wherein a shutoff valve means is positioned in said fuel line adjacent said flow control valve for stopping the flow of fuel to said nozzle means.

7. A fuel system according to claim 6 wherein said shut-off valve means comprises a solenoid operated valve adapted to be electrically connected to an automobile ignition switch to open when the switch is closed.

8. A fuel system according to claim 1 wherein an adjustable valve is placed in said fuel line between said flow control valve and said nozzle means.

9. A fuel system according to claim 1 wherein said valve means comprises a butterfly valve connected to a rod extending through said manifold with its axis normal to said cylindrical rod. 

1. A port injection fuel system for an internal combustion engine comprising an intake manifold having a wall defining an internal passageway through said manifold and having an inlet end and an outlet end, means at said outlet end adapted for attachment to a said engine, said wall having an opening defining a fuel discharge opening near said outlet end, throttle valve means for controlling the flow of air through said intake manifold, said valve means having an open position and a closed position in said manifold to control air flow therethrough, injection nozzle means comprising a slender hollow cylindrical rod disposed centrally across said manifold nearer said inlet end than said valve means and positioned normal to the axis of said intake manifold, said rod having a plurality of spaced bores positioned transverse thereto and axially of said intake manifold, for dispensing vaporized fuel into the air drawn through said intake manifold over said rod, a fuel line connected to said nozzle means, a flow control valve connected to said fuel line to meter the amount of fuel to pass through the line to said nozzle means, said valve comprising a movable valve member and means connected to said valve means for controlling the flow of air and to said valve member to increase the amount of fuel metered to said fuel line and said nozzle means as said throttle valve means is moved to increase the air flow through said intake manifold, means for maintaining fuel in said flow control valve to be metered by said movable valve member to said nozzle means at a pressure sufficient to maintain fuel in said rod across the width of said manifold when said valve means is in said open position; and means for removing air from the fuel line between said means for maintaining fuel in said flow control valve and said flow control valve.
 2. A fuel system according to claim 1 wherein said means for maintaining fuel in said flow control valve comprises a pump and accumulator.
 3. A fuel system according to claim 1 wherein said valve means restricts said opening in said wall in said closed position.
 4. A fuel system according to claim 1 wherein said nozzle means is formed with a pair of restricted bores extending diametrically through said rod adjacent each end near the manifold walls and spaced bores extending only from the side of said rod toward the valve means to the center of said rod.
 5. A fuel system according to claim 4 wherein said rod has an outside diameter of between 0.060 and 0.20 inch, a central bore of between 0.020 and 0.125 inch and said transverse bores have a diameter of between 0.020 and 0.10 inch.
 6. A fuel system accordinG to claim 1 wherein a shut-off valve means is positioned in said fuel line adjacent said flow control valve for stopping the flow of fuel to said nozzle means.
 7. A fuel system according to claim 6 wherein said shut-off valve means comprises a solenoid operated valve adapted to be electrically connected to an automobile ignition switch to open when the switch is closed.
 8. A fuel system according to claim 1 wherein an adjustable valve is placed in said fuel line between said flow control valve and said nozzle means.
 9. A fuel system according to claim 1 wherein said valve means comprises a butterfly valve connected to a rod extending through said manifold with its axis normal to said cylindrical rod. 